The present invention relates to a control valve for use in controlling supply and exhaust of fluid to and from a tourniquet system. Control valves generally of the type disclosed herein and valves for controlling tourniquet systems in general are known in the art. Applicant is aware of the following documents generally pertinent to the structure of the valve disclosed herein:
U.S. Pat No. 3,918,490 to Goda discloses a valve for controlling flow between a plurality of inlets and a lesser plurality of outlets. As shown in FIG. 3, each outlet is associated with two inlets. Each valve comprises a cam 50 with a flat surface which, when facing a respective tube 45 or 46, allows flow therepast.
U.S. Pat. No. 4,061,142 to Tuttle shows a valve in FIG. 2 thereof in which a cam 24 acts through biasing springs 28 and 29 to pivot levers 26 and 27 respectively. The levers 26 and 27 have extensions 43 and 44 respectively which engage parallel tubes at 41 and 42 respectively. Thus rotation of the cam member 24 controls the flow of fluid through the tubes.
U.S. Pat. No. 4,282,902 to Haynes discloses a valve for controlling flow of fluid in a series of flexible tubes. As shown in FIG. 3, representative of the invention, a pair of tubes are controlled by cam member a, the rotation of which flexes the levers 16a and 16j to thereby open and close the respective tubes B1 and B5.
U.S. Pat. No. 4,328,834 to Oates, Sr., et al. shows a single valve for controlling fluid flow in two tubes 14 and 16. The valve includes pivoted lever and cam actuator 40.
U.S.S.R. Pat No. 240,423 shows a valve for controlling the flow from one inlet to one of two outlets. The valve includes cam 2 which acts upon levers including projections 3 and 4 formed thereon to control the flow through outlet tubes 9 and 10.
Other patents generally pertinent to the valve aspect of the present invention but less pertinent than the above discussed references are:
U.S. Pat. No. 1,879,631 to Mott, et al., PA1 U.S. Pat. No. 2,996,081 to Wise, PA1 U.S. Pat. No. 3,134,403 to Rudelick, and PA1 German Pat. No. 2,902,356 to Simens. PA1 U.S. Pat. No. 1,147,560 to Shurtleff, PA1 U.S. Pat. No. 3,826,249 to Lee, et al., PA1 U.S. Pat. No. 3,862,629 to Rotta, PA1 U.S. Pat. No. 4,013,069 to Hasty, PA1 U.S. Pat. No. 4,039,039 to Gottfried, PA1 U.S. Pat. No. 4,202,325 to Vellari, et al., PA1 U.S. Pat. No. 4,294,261 to Baker, et al., PA1 Canadian Pat. No. 952,782 to Gottfried, et al., and PA1 French Pat. No. 2,477,867 to Piedelivre.
It is noted that none of the above discussed references shows the concept of a cam actuated supply and exhaust valve operating by the compression of supply and exhaust tubes.
Applicant is further aware of the following documents which are generally pertinent to the concept of controlling flow to a tourniquet system:
U.S. Pat. No. 3,167,067 to Rand discloses a system for controlling inflation and deflation of four tourniquets located on the extremities. The system sequentially keeps three of the four tourniquets inflated while the fourth is exhausted. As motor 28 rotates shaft 26, the valve sequentially inflates the deflated tourniquet while deflating one of the three previously inflated tourniquets.
U.S. Pat. No. 3,465,749 to Moreland, et al. discloses a rotating tourniquet system including the valving of Rand, and with the further provision of pressure relief valving to prevent excess pressure in the four tourniquets.
U.S. Pat. No. 3,825,008 to Shook shows in FIG. 4, a pair of tourniquets 19 and 19a which are alternately inflated for effecting the "Bier block." The control of the inflation of the tourniquets 19 and 19a is by manually operated toggle valves 35 and 35a.
U.S. Pat. No. 4,321,929 to Lemelson, et al. discloses a system for controlling the inflation and deflation of tourniquets 11 and 15 for a leg and arm respectively. Various disclosed body condition sensors control the inflation and deflation of the tourniquets.
Other documents pertinent to the combination subject matter of means for controlling the inflation and or deflation of tourniquets or inflatable cuffs are known to applicant and are listed below:
It is noted that none of the above discussed patents discloses a cam actuated supply and exhaust valve which compresses supply and exhaust tubes to control the inflation and deflation of plurality of tourniquets.